NASHVILLE (AP) — Legislation that would require anyone recording images of animal abuse to submit unedited footage or photos to law enforcement within 48 hours is "constitutionally suspect," according to a state attorney general's opinion Thursday.

A number of groups and celebrities have spoken out against the proposal. The Humane Society of the United States and others say the bill would have a chilling effect on whistleblowers and prevent undercover operations from establishing an ongoing pattern of abuse.

Attorney General Robert Cooper said the bill is questionable on three grounds. They are:

— the scope of the measure's requirements doesn't include enough interest in preventing cruelty to livestock;

— requirements to provide recordings of livestock cruelty to law enforcement could be an impermissible prior restraint;

— and its reporting requirement could "constitute an unconstitutional burden on news gathering."

In addition, he said the measure — dubbed the "ag gag" bill — could violate an individual's Fifth Amendment right against self-incrimination.

Cooper noted that requiring that a criminal offense be reported is present in some areas of Tennessee law. For instance, he said abuse of an adult or child must be reported.

However, he said the animal legislation differs in several aspects from the mandatory child or adult abuse reports.

For example, he said the measure "provides neither confidentiality nor immunity to the person reporting livestock cruelty."

The Humane Society in 2011 secretly filmed video inside a training stable showing caustic substances being applied to Tennessee walking horses' legs and hooves, and the animals being beaten to make them stand. Trainer Jackie McConnell pleaded guilty in federal court in September.

Wayne Pacelle, president and CEO the Humane Society, said in a statement Thursday after the attorney general opinions that Gov. Bill Haslam now has even more reason to veto the proposal. The bill is on Haslam's desk and he said earlier this week that he was waiting on the attorney general's opinion before making a decision on whether to veto it or let it become law.

"Any bill that tries to punish those who expose cruelty, rather than those who perpetrate it, is wrong-headed and reckless," Pacelle said. "Now we know it's constitutionally deficient, too. Governor Haslam has a superabundance of legal and citizen input that should prompt him to veto this overreaching, awful measure."

After the press conference in Clarksville this week, Haslam told reporters that his decision would be affected by the bill's constitutionality.

"At the end of the day, it should be about is the bill constitutional," he said. "Does it encourage the healthy treatment of animals, and is it good public policy that's well-written for the state. That's what we're going to make our decision based on."

Also this week, the American Civil Liberties Union of Tennessee delivered to the governor a petition containing more than 33,000 signatures of people against the measure.

ACLU executive director Hedy Weinberg said the measure "unconstitutionally chills the free speech of citizens and journalists seeking to expose animal cruelty."

"Across the country people are watching Tennessee in the hopes that Governor Haslam stands up for the First Amendment rights of citizens and journalists to document animal abuse without fear of criminalization," Weinberg said. "If the governor vetoes Tennessee's unconstitutional 'Ag Gag' legislation, it could impact other states nationwide considering similar measures."

According to the National Conference of State Legislatures, 13 bills addressing recordings of agricultural operations have been proposed this year in 10 states. Last year, Missouri passed legislation similar to the one before Haslam.